high compression - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

student · 01-19-2002, 01:24 AM

I want to get as much horsepower from my ka24de and I want toknow if 11.5:1 is ok to run on a ka24de. Will my pistons be hitting anything is there anything i have to worry about. Please enlighten me with your knowledge thanks.

Tuck&Poke · 01-19-2002, 10:12 AM

make sure you use premium feul.  93+ octane cause if not youll be hearing the heart breaking sound of knock which is early combustion.

S13Grl · 01-19-2002, 10:16 AM

True, that is pretty high... but you'll be naturally aspirated. Do make sure you use great fuel, good wires, and make sure your ignition is timed to stock specs. You should be OK.

(Edited by S13Grl at 11:18 am on Jan. 19, 2002)

wherezmytofu · 01-19-2002, 05:12 PM

11.5 on 91
12.5 on 93

Ni5mo180SX · 01-20-2002, 05:50 PM

Just installing a set of high compression pistons isnt gonna give you a huge bump of HP. Your head should be rebuilt to take advantage of this too. And do you even know if your valves are gonna be hitting the top of these pistons or what type of pistons to use? What kind of head gasket are you gonna have on there? What kinda plugs? Im just saying I dont think its as easy as "great fuel, good wires, and make sure your ignition is timed to stock specs. You should be OK". Theres a little more to it then that.

duderiffic · 01-20-2002, 06:11 PM

Shouldn't you always use Premium for a 240SX?  That's what my car said... do all 240s say that?

Jeff
98 SE.

240meowth · 01-20-2002, 08:07 PM

yes, they all say "for best performance use preminum gasoline" or somthing like that... wha's the stock compresion ratio on a ka24? and wouldn't go 11.5:1 be killnig your gas?  u'll feel like u're in a ferarrie or somthing

misnomer · 01-20-2002, 09:24 PM

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">u'll feel like u're in a ferarrie or somthing</td></tr></table><span id='postcolor'>

Yerp, that's the idea <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/tounge.gif" border="0" valign="absmiddle" alt=':p'>

240s will run fine on 87 and 89 octane, I usually feed mine 89

Stock compression is 8.5:1 on most 240s

(Edited by misnomer at 10:25 pm on Jan. 20, 2002)

240meowth · 01-20-2002, 09:32 PM

that's more then 30% jump, dosn't that mean 30% more fuel comsumption? and you know ferries get like 8mpg... and stuff...

*AceInHole* · 01-20-2002, 09:54 PM

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">Quote: from misnomer on 9:24 pm on Jan. 20, 2002
Stock compression is 8.5:1 on most 240s
</td></tr></table><span id='postcolor'>

I thought stock compression is 9.6:1 on most 240's.... 9.1:1 on the 90.  

01-20-2002, 10:12 PM

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">Quote: from 240meowth on 10:32 pm on Jan. 20, 2002
that's more then 30% jump, dosn't that mean 30% more fuel comsumption? and you know ferries get like 8mpg... and stuff...
</td></tr></table><span id='postcolor'>

actually i was reading SCC and they said a 1999 got around 30 mpg.......i think it's vipers that get the shitty mpg

tnord · 01-20-2002, 10:23 PM

doesn't the RSX and ITR run like 11.1? i'm sure it gets good gas mileage relatively speaking

misnomer · 01-21-2002, 12:42 AM

Gah, who gets a sports car to worry about gas mileage? <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/tounge.gif" border="0" valign="absmiddle" alt=':p'>

tnord · 01-21-2002, 12:49 AM

poor college kids like me

Ni5mo180SX · 01-21-2002, 02:25 AM

umm, last time I checked, raising your compression wont lower your gas mileage. In fact it might raise it. The stock compression on the KA24E is 8.9.1 from what ive heard.
"ka24? and wouldn't go 11.5:1 be killnig your gas?  u'll feel like u're in a ferarrie or somthing that's more then 30% jump, dosn't that mean 30% more fuel comsumption? and you know ferries get like 8mpg... and stuff... "
Increase in compression means an increase in efficiency which should raise your gas mileage.

240 2NR · 01-21-2002, 07:37 AM

A diesel motor runs somewhere in the neighborhood of 20:1 compression.  Last I checked a TDI gets somewhere in the neighborhood of 45mpg (that has a turbo too).  Higher compression ratios are good, and will usually indicate higher efficiency.  The reason fuel milage may suck is that to be safe, its better to add fuel then take away or stay the same (general rule, please don't reply back with "I know this one car...").  Same with turbos.  You can either run really good engine management and get good milage or throw lots of fuel at it and be safe, but run kind of shitty.

Lots of people have been talking about getting better milage on a KA-T with stock internals over a standard KA on the highway.  Maybe my dad would be happy about the upgrade if I told him that.

Logo · 01-21-2002, 07:43 AM

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">Quote: from AceInHole on 11:54 pm on Jan. 20, 2002
</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">Quote: from misnomer on 9:24 pm on Jan. 20, 2002
Stock compression is 8.5:1 on most 240s
</td></tr></table><span id='postcolor'>

I thought stock compression is 9.6:1 on most 240's.... 9.1:1 on the 90.
</td></tr></table><span id='postcolor'>

You're right dude.  It's 9.6:1

thewholefnshow · 01-21-2002, 07:51 AM

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">Quote: from 240 2NR on 7:37 am on Jan. 21, 2002
A diesel motor runs somewhere in the neighborhood of 20:1 compression. Last I checked a TDI gets somewhere in the neighborhood of 45mpg (that has a turbo too). </td></tr></table><span id='postcolor'>

Yah, but the also don't spin to 6500...

01-19-2002, 01:24 AM	#1
student Leaky Injector Join Date: Dec 2001 Posts: 78 Trader Rating: (0) Feedback Score: 0 reviews	I want to get as much horsepower from my ka24de and I want toknow if 11.5:1 is ok to run on a ka24de. Will my pistons be hitting anything is there anything i have to worry about. Please enlighten me with your knowledge thanks.

01-19-2002, 10:12 AM	#2
Tuck&Poke Zilvia FREAK! Join Date: Aug 2001 Location: MIA Age: 38 Posts: 1,046 Trader Rating: (0) Feedback Score: 0 reviews	make sure you use premium feul.  93+ octane cause if not youll be hearing the heart breaking sound of knock which is early combustion.

01-19-2002, 10:16 AM	#3
S13Grl Married to the Mob Join Date: Dec 2000 Age: 44 Posts: 3,670 Trader Rating: (0) Feedback Score: 0 reviews	True, that is pretty high... but you'll be naturally aspirated. Do make sure you use great fuel, good wires, and make sure your ignition is timed to stock specs. You should be OK. (Edited by S13Grl at 11:18 am on Jan. 19, 2002)

01-19-2002, 05:12 PM	#4
wherezmytofu BANNED Join Date: Nov 2001 Posts: 1,873 Trader Rating: (0) Feedback Score: 0 reviews	11.5 on 91 12.5 on 93

01-20-2002, 05:50 PM	#5
Ni5mo180SX Zilvia Junkie Join Date: Dec 2001 Location: Orange County Posts: 423 Trader Rating: (0) Feedback Score: 0 reviews	Just installing a set of high compression pistons isnt gonna give you a huge bump of HP. Your head should be rebuilt to take advantage of this too. And do you even know if your valves are gonna be hitting the top of these pistons or what type of pistons to use? What kind of head gasket are you gonna have on there? What kinda plugs? Im just saying I dont think its as easy as "great fuel, good wires, and make sure your ignition is timed to stock specs. You should be OK". Theres a little more to it then that.

01-20-2002, 06:11 PM	#6
duderiffic Zilvia Junkie Join Date: Jan 2002 Location: Bay Area (Sunnyvale) Age: 43 Posts: 464 Trader Rating: (0) Feedback Score: 0 reviews	Shouldn't you always use Premium for a 240SX?  That's what my car said... do all 240s say that? Jeff 98 SE.

01-20-2002, 08:07 PM	#7
240meowth Nissanaholic! Join Date: Dec 2001 Location: torrance, ca Age: 41 Posts: 2,407 Trader Rating: (4) Feedback Score: 4 reviews	yes, they all say "for best performance use preminum gasoline" or somthing like that... wha's the stock compresion ratio on a ka24? and wouldn't go 11.5:1 be killnig your gas?  u'll feel like u're in a ferarrie or somthing

01-20-2002, 09:24 PM	#8
misnomer Nissanaholic! Join Date: Jul 2001 Location: Nevada Posts: 2,293 Trader Rating: (0) Feedback Score: 0 reviews	</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">u'll feel like u're in a ferarrie or somthing</td></tr></table><span id='postcolor'> Yerp, that's the idea <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/tounge.gif" border="0" valign="absmiddle" alt=':p'> 240s will run fine on 87 and 89 octane, I usually feed mine 89 Stock compression is 8.5:1 on most 240s (Edited by misnomer at 10:25 pm on Jan. 20, 2002)

01-20-2002, 09:32 PM	#9
240meowth Nissanaholic! Join Date: Dec 2001 Location: torrance, ca Age: 41 Posts: 2,407 Trader Rating: (4) Feedback Score: 4 reviews	that's more then 30% jump, dosn't that mean 30% more fuel comsumption? and you know ferries get like 8mpg... and stuff...

01-20-2002, 09:54 PM	#10
AceInHole Autox Technician Join Date: Dec 2001 Location: New Haven, CT Age: 44 Posts: 3,961 Trader Rating: (0) Rides Gallery: AceInHole Feedback Score: 0 reviews	</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">Quote: from misnomer on 9:24 pm on Jan. 20, 2002 Stock compression is 8.5:1 on most 240s </td></tr></table><span id='postcolor'> I thought stock compression is 9.6:1 on most 240's.... 9.1:1 on the 90.

01-20-2002, 10:12 PM	#11
Guest Posts: n/a	</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">Quote: from 240meowth on 10:32 pm on Jan. 20, 2002 that's more then 30% jump, dosn't that mean 30% more fuel comsumption? and you know ferries get like 8mpg... and stuff... </td></tr></table><span id='postcolor'> actually i was reading SCC and they said a 1999 got around 30 mpg.......i think it's vipers that get the shitty mpg

01-20-2002, 10:23 PM	#12
tnord Nissanaholic! Join Date: Dec 2001 Posts: 1,975 Trader Rating: (0) Feedback Score: 0 reviews	doesn't the RSX and ITR run like 11.1? i'm sure it gets good gas mileage relatively speaking

01-21-2002, 12:42 AM	#13
misnomer Nissanaholic! Join Date: Jul 2001 Location: Nevada Posts: 2,293 Trader Rating: (0) Feedback Score: 0 reviews	Gah, who gets a sports car to worry about gas mileage? <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/tounge.gif" border="0" valign="absmiddle" alt=':p'>

01-21-2002, 12:49 AM	#14
tnord Nissanaholic! Join Date: Dec 2001 Posts: 1,975 Trader Rating: (0) Feedback Score: 0 reviews	poor college kids like me

01-21-2002, 02:25 AM	#15
Ni5mo180SX Zilvia Junkie Join Date: Dec 2001 Location: Orange County Posts: 423 Trader Rating: (0) Feedback Score: 0 reviews	umm, last time I checked, raising your compression wont lower your gas mileage. In fact it might raise it. The stock compression on the KA24E is 8.9.1 from what ive heard. "ka24? and wouldn't go 11.5:1 be killnig your gas?  u'll feel like u're in a ferarrie or somthing that's more then 30% jump, dosn't that mean 30% more fuel comsumption? and you know ferries get like 8mpg... and stuff... " Increase in compression means an increase in efficiency which should raise your gas mileage.

01-21-2002, 07:37 AM	#16
240 2NR Zilvia FREAK! Join Date: Dec 2001 Location: Denver Posts: 1,131 Trader Rating: (0) Feedback Score: 0 reviews	A diesel motor runs somewhere in the neighborhood of 20:1 compression.  Last I checked a TDI gets somewhere in the neighborhood of 45mpg (that has a turbo too).  Higher compression ratios are good, and will usually indicate higher efficiency.  The reason fuel milage may suck is that to be safe, its better to add fuel then take away or stay the same (general rule, please don't reply back with "I know this one car...").  Same with turbos.  You can either run really good engine management and get good milage or throw lots of fuel at it and be safe, but run kind of shitty. Lots of people have been talking about getting better milage on a KA-T with stock internals over a standard KA on the highway.  Maybe my dad would be happy about the upgrade if I told him that.

01-21-2002, 07:43 AM	#17
Logo Join Date: Jul 2001 Posts: 48 Trader Rating: (0) Feedback Score: 0 reviews	</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">Quote: from AceInHole on 11:54 pm on Jan. 20, 2002 </span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">Quote: from misnomer on 9:24 pm on Jan. 20, 2002 Stock compression is 8.5:1 on most 240s </td></tr></table><span id='postcolor'> I thought stock compression is 9.6:1 on most 240's.... 9.1:1 on the 90. </td></tr></table><span id='postcolor'> You're right dude.  It's 9.6:1

01-21-2002, 07:51 AM	#18
thewholefnshow Zilvia Addict Join Date: Nov 2001 Posts: 672 Trader Rating: (0) Feedback Score: 0 reviews	</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">Quote: from 240 2NR on 7:37 am on Jan. 21, 2002 A diesel motor runs somewhere in the neighborhood of 20:1 compression. Last I checked a TDI gets somewhere in the neighborhood of 45mpg (that has a turbo too). </td></tr></table><span id='postcolor'> Yah, but the also don't spin to 6500...